Wet battery and vehicle-based water management system

ABSTRACT

A water management system for a motor vehicle in which water is collected from the condenser ( 1 ) of the air-conditioning unit, stored in a master water tank ( 5 ) and distributed therefrom to the battery ( 15 ), screen wash jet ( 27 ) and radiator ( 37 ). The vehicle owner is thus spared the inconvenience of regularly checking and topping up the water supply for these items. The risk of breakdown is also reduced. In another aspect of the invention, a wet battery ( 15 ) incorporates a plurality of float valves ( 75 ) for regulating the fluid level in respective cells ( 61, 63 ) of the battery. Water is passed through a common channel ( 23 ) into which the float valves ( 75 ) open when the fluid level is below a preset limit. The battery fluid is thereby automatically kept at the required level for optimum performance and lifetime of the battery.

CROSS-REFERENCE TO RELATED APPLICATIONS, IF ANY

This application is a divisional of application Ser. No. 09/089,756,filed Jun. 2, 1998, which issued to U.S. Pat. No. 6,209,573 B1 on Apr.3, 2001, which is hereby incorporated by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX, IF ANY

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a wet battery which needs to be topped upperiodically with water or other fluid. The invention also relates to avehicle-based water management system for use in connection with atleast one unit on the vehicle which requires water for its operation.

2. Description of the Prior Art

In a motor vehicle such as a car, there are a number of units whichrequire water for their operation and in which the supply of water mustbe regularly checked and topped up if necessary. These units include theradiator, the screen wash and the battery. Water is lost from theradiator due to leakage and evaporation. Water is consumed in normal useof the screen wash. Water is lost from the battery through evaporationand boiling caused by heating of the battery during its charging anddischarging cycle and due to the engine temperature. In an electricvehicle, the batteries constitute the source of motive power, so it isparticularly important that they be maintained in good condition at alltimes.

Presently, the vehicle owner must routinely inspect and refill the watersupply in all these units. This is an inconvenient and irritatingburden, yet damage may result or safety be compromised if the task isnot done. Additionally, the water level in the cells of the or eachbattery should be carefully adjusted in order to optimize theperformance and lifespan. This is particularly important in the case ofan electric car or other vehicle. However, getting the water level rightrequires some skill and knowledge. Moreover, the need to check and filleach cell individually is time-consuming.

The present invention arose partly from a consideration of theseproblems and how they may be overcome.

SUMMARY OF THE INVENTION

In one aspect, the invention provides a wet battery comprising aplurality of cells, each cell having a respective fluid inlet, thebattery having a channel which is shared by the fluid inlets forsupplying fluid such as water to the cells of the battery, wherein eachcell includes a float valve associated with its fluid inlet and arrangedto automatically open for communication with the channel when the fluidin the cell is below a predetermined level.

According to this aspect of the invention, the procedure of maintainingthe fluid level of each cell of the battery is simplified and may beautomatically regulated, thereby ensuring optimum performance andlifespan.

In a preferred embodiment, the battery has an integral reservoir fortemporarily holding a quantity of water. The reservoir is periodicallyfilled manually or automatically, and then empties its content throughthe channel, which supplies the cells as required. Any excess waterexits the channel through an overflow or may even be returned to thereservoir. According to this arrangement, the fluid level isautomatically set by the valves and it is impossible to overfill thebattery.

In another aspect, the invention provides a water management system on avehicle, the system comprising water collecting means for providing asupply of water and distribution means for distributing the water fromthe supply to a plurality of units on the vehicle which require waterfor their operation.

According to this other aspect of the invention, a supply of water isalways conveniently available for use by the units requiring water fortheir operation. The plurality of units may consist of a bank of two ormore batteries in the case of an electric vehicle.

The water collecting means may be a master or central storage vesselwhich is filled manually. However, the water collecting means mayinclude a source which generates water as a by-product. In oneembodiment of the invention, an air-conditioning system is employed toprovide the water supply. The condensate formed on the condenser of theair-conditioning system offers a reliable and clean source of water. Itis also simple to collect, for example by using the conventional drippipe of the condenser to feed the condensed water into a storage tank.

The inventor has tested the system on his own car and found thatone-half of a litre of water may be collected from the car'sair-conditioner in one 30-minute city journey. This result indicatesthat more than a sufficient amount of water to meet the usualrequirements of the radiator, screen wash and battery can be collectedin this way. Thus, an adequate supply of water to those units may beguaranteed. A sample of the collected water was tested and found to havea pH value of 6.4, i.e. substantially neutral. This further demonstratesthe fitness of the collected water.

The automatic supply of the collected water to the units means that thevehicle owner is spared the inconvenience of having to regularly checkand top up the units. Thus, the maintenance effort is beneficiallyreduced and the risk of breakdown is lowered. The collected water mayalso be used to provide a supply of drinking or washing water within thecar.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, in its various aspects, is illustrated, but not limited,by the following description of an embodiment, which refers to theaccompanying drawings.

FIG. 1 is a schematic illustration of a water management system inaccordance with the invention;

FIG. 2(a) shows an internal view of a wet battery in accordance with theinvention;

FIG. 2(b) shows a component of the float valve of the battery of FIG.2(a);

FIG. 2(c) is an enlarged view of the float valve of the battery of FIG.2(a);

FIG. 2(d) shows another component of the float valve of the battery ofFIG. 2(a); and

FIG. 3 shows an external view of the battery of FIG. 2(a).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, and first FIG. 1, there is shown a watermanagement apparatus for a motor car. The condenser unit 1 of the car'sair-conditioning system serves as a source of water supply. Watergenerated in the condenser unit 1 is supplied to a central storage tank5 via a pipe 2 and filter 3. The pipe 2 is connected to the drip outletof the condenser unit 1. In this embodiment, the filter 3 is amechanical filter for removing any dust, dirt or other solid contaminantfrom the collected water. The filter 3 is conveniently incorporated intothe cap 4 of the tank 5. The cap includes an overflow outlet 16 forexcess water to be discharged when the tank 5 is full.

The filtered water is fed from the tank 5, through piping 6, to aplurality of water storage tanks or bottles 7, 11, 13 and to a batterywater reservoir 9 (see FIG. 3). For this purpose, a pump 33 isassociated with the tank 5. The pump may be operated automatically or bymeans of a control within the vehicle in order to periodically top upthe supplies 7, 9, 11 and 13.

A water reservoir 9, best seen in FIG. 3, is arranged for supplyingwater to the car's battery 15. The water in the reservoir 9 is allowedto drain, under the action of gravity, through a channel 23 whichsupplies water to the battery cells. Any excess or unrequired water 25escapes at an outlet of the channel. The arrangement of the reservoir 9and channel 23 for supplying water to the battery 15 will be describedlater with reference to FIGS. 2 and 3.

One water storage tank 11 is arranged for supplying water to a screenwasher unit comprising one or more spray jets 27. In FIG. 1, the jet 27is associated with a windscreen wiper 29. However, the jet may beequally provided for cleaning a rear window or a car light, especially aheadlight. A pump 35, which is operated by means of a switch or lever onthe dashboard or steering column, serves to supply water to the jet 27through a pipe 12 in conventional manner.

The tank 11 may contain a cleaning agent. Water is fed into the tank 11from the master tank 5 via a ball-valve 18 or the like. The valve 18 isclosed when the tank 11 is full, so that any further water is dischargeddirectly through an overflow 20. This arrangement ensures that there isno loss of cleaning agent when the tank 11 is full. Since the tank 11 isregularly filled with water from the master supply, its capacity can bemade smaller than the conventional screen wash tank.

Another water storage tank 13 provides a supply of water for theradiator 37 of the engine's cooling system. Water is sucked up to theradiator 37 from the tank 13 through a pipe 14. A valve 22 and overflowoutlet 24 arrangement, similar to that provided for the tank 11, ensurethat any coolant agent contained in the cooling system is not lost whenthe tank 13 is full.

A further water storage tank 7 provides a supply of water for drinking,handwashing or the like by the driver and any passengers. A pump 31serves to pump the water to an outlet through a pipe 8, when required.The outlet is preferably located in the car interior, although it may belocated elsewhere, for example in the boot. An overflow pipe 26discharges any excess water when the tank 7 is full.

Each of the pipes 2, 6, 8, 12 and 14 which interconnect the variouscomponents of the system, suitably consists of flexible tube or hose ofrubber or other water-impermeable material.

The storage bottles 11, 13 and the battery 15 are preferably disposed intheir normal positions within the engine compartment, that is inpositions where they are accessible for inspection and the occasionaladdition of screen wash detergent or engine coolant. Therefore, fittingthe water management system of the invention to an existing vehicle doesnot require extensive modification of the layout of the components ofthe engine compartment.

FIGS. 2(a)-(d) and 3 illustrate the construction of part of a wetbattery in accordance with an independent aspect of the invention. Inthis specification, the term wet battery refers to a battery containingfluid which needs to be periodically topped up. Although the wet batteryto be described is particularly suitable for use in the water managementsystem of FIG. 1, it is not limited to such an application.

Referring first to FIG. 2(a), the battery 15 of this embodiment has sixcells arranged in a linear array in conventional manner. For thepurposes of illustration, only two of the cells 61, 63 are shown in fullin FIG. 2(a). The other cells are the same. Each cell 61, 63 comprises acollection of plate-like electrodes 65 immersed in electrolyte fluid 67.A structural wall 69 separates, and isolates the fluid in, the adjacentcells.

The upper wall of each cell is defined by the bottom of the waterchannel 23, already mentioned with reference to FIG. 1. The channel 23extends over the line of cells to allow water, or other fluid, flowingalong the channel to enter the cells as required. For this purpose, thebottom of the channel includes two apertures for each cell. Referring tothe enlarged view of FIG. 2(c), a first aperture serves as a gas vent,to permit gas or air to escape from the battery as required. The firstaperture consists of a chimney-like structure 71, which extends to alevel above the normal water level in the channel 23, thereby preventingunwanted entrance of water through the gas vent. Alternatively, thechannel 23 may include an internal wall extending longitudinally thereinto isolate the gas vents 71 from the water-receiving portion of thechannel. A second aperture 81 serves as a water inlet for the cell, topermit water to enter the cell to top up the electrolyte level. Thissecond aperture 81 consists of a hole surrounded internally by acylindrical guide wall 73.

A float valve member 75 is disposed within each cell. The float valvemember 75 has three main portions: a float portion 75 a, a valve portion75 b, and a cup portion 75 c. The float portion 75 a extends laterally,suitably in a circular or rectangular shape, and floats on the surfaceof the battery fluid 67. The float portion 75 a is suitably made ofStyrofoam (trademark). The valve portion 75 b, which is shown in detailin FIG. 2(b), extends vertically from the centre of the float portion 75a and is supported and guided by the guide wall 73. The distal end ofthe cylindrical valve portion 75 b is terminated in a sealing disc 75 jwhich internally engages the peripheral portion of the water inletaperture 81 in a sealing manner when the valve is closed. The sealingdisc 75 j is made of a resilient and water-impermeable material. The useof silicone rubber for the sealing disc is presently preferred.

As best seen in FIG. 2(b), the valve portion 75 b comprises a pluralityof radial vanes 75 d extending longitudinally and spacedcircumferentially. The vanes 75 d serve to locate the valve portion 75 bcentrally within the surrounding guide cylinder 73, and thereby form aplurality of passageways between the valve portion 75 b and the innersurface of the wall 73. The passageways allow the free flow of waterinto the cell when the valve is open.

This preferred configuration also prevents the accumulation of dirt suchas oxide particles on the valve portion 75 b, and so ensures the freemovement of the valve portion even when the fluid environment within thebattery becomes contaminated as the battery ages.

Referring again to FIG. 2(b), the valve portion 75 b further includes amounting disc 75 e which provides an annular flange. The portions of thevanes 75 d below the disc 75 e are adapted to be received in a lowercylinder 75 h of the cup portion 75 c.

FIG. 2(d) shows the cup portion 75 c of the float valve member 75. Thiscomprises an upper hollow cylindrical element 75 k, which is open at thetop end and has a diameter greater than that of the guide wall 73. Thecup portion further comprises a lower hollow cylindrical element 75 h ofa diameter which is smaller than that of the upper element 75 k andslightly greater than that of the valve portion 75 b. The lowercylindrical element 75 h is closed at its bottom end.

As best seen in FIG. 2(c), the lower element 75 h accommodates the lowerportion of the valve body 75 b. The flange of the disc 75 e is seated onthe step which joins the upper and lower cylindrical elements 75 k, 75h. The disc flange is preferably sealingly fixed to the step, forexample by using adhesive.

The lower portion of the upper cylindrical element 75 k includes aplurality of fluid holes 75 g. The fluid holes 75 g are formed in thecylinder wall, at a certain height above the step.

The vertical movement of the float valve member 75 is limited in thedownward direction by interlocking of the cup portion 75 c with theguide wall 73. For this purpose, in this embodiment, the lower end ofthe guide wall terminates in an annular lip 73 a (see FIG. 2(c)), whilethe top, open end of the cup portion 75 c includes a plurality ofinternal lugs 75 f (see FIG. 2(d). When the float valve member 75 dropsbelow a predetermined level, the lugs 75 f (there are two by way ofexample in the present embodiment) latch onto the guide wall lip 73 a toarrest further downward movement. The vertical movement in the upwarddirection is limited by the engagement of the sealing disc 75 j with thewater inlet aperture 81 when the valve is in the closed state.

It will be noted that guide wall 73 and the wall of the upper element 75k of the cup portion form a continuous vertical barrier extending fromthe cell ceiling to the valve float portion 75 a. This arrangementserves to prevent the escape of fluid from the cell (via the said secondaperture), especially during vibration when the vehicle is in motion.Any fluid which does enter the cup portion will, however, flow outthrough the holes 75 g therein when the fluid exceeds the level of thoseholes. As a further safeguard against the escape of fluid, a cylindricalbaffle wall 77 extends vertically down from the cell ceiling to surroundthe upper part of the valve member 75. The arrows 79 indicate thefunction of the baffle wall 77 in deflecting any fluid that splashesupwards within the cell.

The inclusion of the cup portion 75 c is optional, since the valve willoperate without it. However, it is preferred for the reasons andadvantages set out herein.

FIG. 3 is a perspective view of the top of the battery showing thechannel 23 and reservoir 9 mentioned already with reference to FIG. 1.In this embodiment, the channel 23 and the reservoir 9 are formed as anintegral box-like structure 39, which is conveniently made as a plasticmoulding. An internal wall 41 divides the structure into the fluidreservoir 9 and the supply channel 23. The upper wall of the box may beremovable or openable (not shown), especially over the channel 23 topermit inspection. The box is preferably also made of clear plastic forthis purpose. The portion of the upper wall or lid over the channelencourages condensation of any battery fluid vapour escaping from thevents 71. The condensate usefully collects in the bottom of the channeland thus may reduce the amount of water that needs to be supplied fromthe reservoir.

Water is pumped into the reservoir 9 by the pump 33 (see FIG. 1) throughan inlet 43 and enters the channel 23 therefrom via a port 45 formed inthe wall 41. The water flows down the channel 23 and enters each cell ofthe battery whose fluid level is such that the float valve aperture 81is open. Any excess water exits from the outlet 47, from where it may bewasted or returned to the reservoir 9 or tank 5. It is not essential tofill the reservoir 9 automatically. In an application where a watermanagement system such as that shown in FIG. 1 is not employed, a manualfilling port 49 and associated plug 51 can be provided. In that case,the inlet 43 is either plugged or not provided at all.

The reservoir 9, channel 23 and float valve members 75 may beconstituted as a cover assembly to be fitted to the body of aconventional battery, thereby enabling the battery manufacturer tofabricate a battery in accordance with the invention without the need tore-design or re-tool the body of the battery.

In operation, water is fed into the channel 23 through the port 45 andtravels down the channel toward the end having the outlet 47. For anycell of the battery in which the fluid level is below a predeterminedvalue, the float valve member 75 will drop down to open a gap betweenthe aperture 81 and sealing disc 75 j. Thus, the water will enter thiscell through the gap.

The water flows down between the guide wall 73 and the valve body 75 b,enters the bottom of the cup 75 c and exits through the fluid holes 75g, thereby topping up the cell fluid level. When the fluid level hasrisen again to the reference value, the float valve member 75 will alsoreside at a higher level to close the gap thereby preventing furtherwater entry. The fluid level in each cell is self-regulated in this way.The cells may be topped up, as required, either in sequence orsimultaneously, depending on the speed of the water flow through thechannel. The water may be supplied to the channel 23 continuously orperiodically. In the system of FIG. 1, the reservoir 9 is periodicallycharged, whether by manual instruction or automatically, and thenallowed to empty over a short period, suitably a few minutes. Thisintermittent mode of operation is preferred to using a continuous flowof water. Especially, the intermittent flow of water can be generatedwhen the vehicle is not in motion, which prevents accidental opening ofthe cell valves and unwanted entry of water due to vibration or shock.

The advantages of the described construction of the wet battery includethe following. The provision of the common channel serving to supply thewater to all the battery cells means that there is no need tointerconnect the individual cell valves. Also, as compared with using ahose connection, the channel is easily accessible, less liable toblockage and simple to clean. Building the float valves into thestructure of battery body enables each float member to occupy the fullwidth of the cell. This improves the weight of the float valve memberand the response to changes in the fluid level. The construction of thevalves is simple and therefore of low cost, yet reliable. The water usedto top up the cells does not need to be pressurised, nor suppliedcontinuously.

The water management system of the invention is suitable for use on anyvehicle including car, electric car, lorry, bus, train, boat, ship andvarious kinds of aircraft. Any one or more units requiring a watersupply may be incorporated. It is not essential to supply water to thefour units of the example, although in the case of the car, it isconvenient to do so. Some modern vehicle batteries are completely sealedand do not require water top up. Here, the system remains suitable forany or all of the radiator, screen wash and drinking supplies. The wetbattery of the invention has application in the above vehicles plusvehicles such as fork lift trucks and milk floats which use electricalpower for their traction and/or other functions. The battery of theinvention is equally useful in applications outside of the field ofvehicles, such as emergency and stand-by power supplies.

What is claimed is:
 1. A battery comprising: (a) a body, said body beingdivided internally into a plurality of battery cells; (b) fluidcontained in said body, said fluid having a respective fluid level ineach of said battery cells; (c) each said battery cell having arespective fluid inlet for entry of fluid into said cell to change saidfluid level in said cell; (d) a fluid channel for supplying said fluidto said battery cells, said fluid channel communicating with said fluidinlets of said battery cells; and (e) each said battery cell having arespective float valve arranged inside said body of said battery foropening and closing of said fluid inlet of said cell; (f) wherein, whensaid fluid level of said cell falls below a predetermined fluid level,said float valve of said cell is opened to permit fluid to enter saidcell from said channel via said fluid inlet; (g) wherein, when saidfluid level of said cell reaches said predetermined level, said floatvalve of said cell is closed to prevent fluid from entering said cellfrom said channel via said fluid inlet; and (h) wherein said fluidchannel is integral to said battery and includes an inlet port at oneend of said fluid channel and an outlet port at another end of saidfluid channel, whereby fluid may flow intermittently through saidchannel, from said inlet port to said outlet port, over said fluidinlets of said cells to supply said fluid to said cells, and any excessfluid exits from said outlet port.
 2. A battery according to claim 1,wherein said float valve comprises a float valve member having a floatportion, a valve portion and a cup portion, said float portioncontrolling opening and closing of said float valve according to saidfluid level, said valve portion arranged for fluid-sealing engagement ofa periphery of said fluid inlet when said float valve is closed, andsaid cup portion including a wall which serves as a barrier to preventsaid fluid from exiting said cell through said fluid inlet and whichlimits valving movement of said float valve member.
 3. A batteryaccording to claim 1, further comprising a fluid reservoir communicatingwith said channel.
 4. A battery according to claim 3, wherein saidchannel and said reservoir include an internal wall which is common tosaid channel and said reservoir, said internal wall including said inletport which enables said fluid to flow into said channel from saidreservoir.